Advances in digital satellite technology have resulted from a combination of improvements in digital compression techniques, forward error correction, and integrated circuit (IC) technology. These advances have given users of satellite systems the ability to communicate between distant points on the globe via orbiting relay satellites. These systems provide the capability of transmitting or receiving video, audio or data nearly instantaneously.
Data relayed from satellite systems can be especially useful to personnel who require instantaneous access to large amounts of data while in remote field locations. This data can include audio, video, or other information needed to facilitate the performance of field-related tasks. For example, groups of military troops could benefit from viewing video maps transmitted to the field by forward reconnaissance aircraft via relay satellites. Search-and-rescue operations could also benefit from sharing information instantaneously among constantly moving personnel scattered throughout a large geographic area. Furthermore, satellite-relayed television would certainly be useful in remote outdoor recreational activities.
Presently available consumer satellite receiver systems may also transmit television, audio, or data signals which can be useful in the field. For example, new digital direct broadcast satellite (DBS) systems, which can allow the reception of over 100 channels of digital satellite television using small, affordable satellite receiver antennas, may be used to implement the above audio, data, or image reception requirements in remote areas.
Modern direct broadcast satellites transmit with significantly greater output power than conventional satellites. Signals transmitted from these high-power DBS satellites reach the earth with an effective power several orders of magnitude greater than signals broadcast from conventional satellites. In addition, new gallium arsenide (GaAs) IC amplifiers have significantly improved the sensitivity of the receiver electronics. Accordingly, the size of the antenna required to receive DBS television programming has been reduced from several meters to 18 inches or less in diameter.
Despite the significant reduction in the size of the required antenna, DBS television reception has been generally limited to fixed, permanent installations. In a typical installation, the DBS antenna is aimed at the desired satellite and permanently mounted outside the subscriber's home. A coaxial cable from the antenna is run to an integrated receiver/decoder (IRD) unit located inside the home. The IRD is typically housed in a VCR-sized consumer electronics unit requiring a 110-volt AC electrical power source. During operation, the IRD receives a satellite signal and outputs a television signal suitable for display on a household television set, which itself usually requires a large power source.
Therefore, DBS satellite television reception is not generally available where a permanently mounted fixed receiver dish antenna is unfeasible or where available power is limited. For example, few options exist for installing DBS systems on boats, recreational vehicles, or campers. Current approaches for offering transportable DBS television reception often use the same cumbersome devices used in permanent installations such as a parabolic reflector antenna and a bulky television monitor to display the images. One approach includes a tripod mount for temporarily positioning the parabolic reflector antenna. Another approach includes a smaller (14-inch) antenna with temporary mounts and a DC-to-AC power converter which can operate the IRD unit off of a battery supply.
Furthermore, satellite signal decoders are generally not capable of providing services other than satellite signal decoding. It would be beneficial, however, to provide a stationary or portable satellite signal decoder with the ability to provide numerous other user services besides satellite signal decoding to make these devices more versatile.
As a result, many needed applications of highpower satellite communications systems remain untapped. Various consumer and/or field uses, such as the search-and-rescue or military reconnaissance applications described above, could benefit from the use of DBS technology to facilitate audio, video, or data reception in remote areas or to constantly moving personnel.